C * -points vs P -points and P -points

Jorge Martinez; Warren Wm. McGovern

Commentationes Mathematicae Universitatis Carolinae (2022)

  • Volume: 62 63, Issue: 2, page 245-259
  • ISSN: 0010-2628

Abstract

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In a Tychonoff space X , the point p X is called a C * -point if every real-valued continuous function on C { p } can be extended continuously to p . Every point in an extremally disconnected space is a C * -point. A classic example is the space 𝐖 * = ω 1 + 1 consisting of the countable ordinals together with ω 1 . The point ω 1 is known to be a C * -point as well as a P -point. We supply a characterization of C * -points in totally ordered spaces. The remainder of our time is aimed at studying when a point in a product space is a C * -point. This process leads to many interesting new discoveries.

How to cite

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Martinez, Jorge, and McGovern, Warren Wm.. "$C^*$-points vs $P$-points and $P^\flat $-points." Commentationes Mathematicae Universitatis Carolinae 62 63.2 (2022): 245-259. <http://eudml.org/doc/298541>.

@article{Martinez2022,
abstract = {In a Tychonoff space $X$, the point $p\in X$ is called a $C^*$-point if every real-valued continuous function on $C\setminus \lbrace p\rbrace $ can be extended continuously to $p$. Every point in an extremally disconnected space is a $C^*$-point. A classic example is the space $\{\bf W\}^*=\omega _1+1$ consisting of the countable ordinals together with $\omega _1$. The point $\omega _1$ is known to be a $C^*$-point as well as a $P$-point. We supply a characterization of $C^*$-points in totally ordered spaces. The remainder of our time is aimed at studying when a point in a product space is a $C^*$-point. This process leads to many interesting new discoveries.},
author = {Martinez, Jorge, McGovern, Warren Wm.},
journal = {Commentationes Mathematicae Universitatis Carolinae},
keywords = {ring of continuous functions; $C^*$-embedded; $P$-point},
language = {eng},
number = {2},
pages = {245-259},
publisher = {Charles University in Prague, Faculty of Mathematics and Physics},
title = {$C^*$-points vs $P$-points and $P^\flat $-points},
url = {http://eudml.org/doc/298541},
volume = {62 63},
year = {2022},
}

TY - JOUR
AU - Martinez, Jorge
AU - McGovern, Warren Wm.
TI - $C^*$-points vs $P$-points and $P^\flat $-points
JO - Commentationes Mathematicae Universitatis Carolinae
PY - 2022
PB - Charles University in Prague, Faculty of Mathematics and Physics
VL - 62 63
IS - 2
SP - 245
EP - 259
AB - In a Tychonoff space $X$, the point $p\in X$ is called a $C^*$-point if every real-valued continuous function on $C\setminus \lbrace p\rbrace $ can be extended continuously to $p$. Every point in an extremally disconnected space is a $C^*$-point. A classic example is the space ${\bf W}^*=\omega _1+1$ consisting of the countable ordinals together with $\omega _1$. The point $\omega _1$ is known to be a $C^*$-point as well as a $P$-point. We supply a characterization of $C^*$-points in totally ordered spaces. The remainder of our time is aimed at studying when a point in a product space is a $C^*$-point. This process leads to many interesting new discoveries.
LA - eng
KW - ring of continuous functions; $C^*$-embedded; $P$-point
UR - http://eudml.org/doc/298541
ER -

References

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  1. Darnel M. R., Theory of Lattice-ordered Groups, Monographs and Textbooks in Pure and Applied Mathematics, 187, Marcel Dekker, New York, 1995. Zbl0810.06016MR1304052
  2. van Douwen E. K., Remote Points, Dissertationes Math., Rozprawy Mat. 188 (1981), 45 pages. MR0627526
  3. Dow A., Henriksen M., Kopperman R., Woods R. G., Topologies and cotopologies generated by sets of functions, Houston J. Math. 19 (1993), no. 4, 551–586. MR1251610
  4. Engelking R., General Topology, Sigma Series in Pure Mathematics, 6, Heldermann Verlag, Berlin, 1989. Zbl0684.54001MR1039321
  5. Gillman L., Jerison M., Rings of Continuous Functions, Graduate Texts in Mathametics, 43, Springer, New York, 1976. Zbl0327.46040MR0407579
  6. McGovern W. W., 10.1023/B:AMHU.0000049288.46182.1e, Acta Math. Hungar. 105 (2004), no. 3, 215–230. MR2100854DOI10.1023/B:AMHU.0000049288.46182.1e

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